Detroit Dam

On the North Santiam River in Oregon, a tributary of the Willamette draining from the Cascades. The dam was built in the early 1950s, before blocking salmon streams was an issue! It backs up Detroit Lake. It _does_ generate hydropower; the inset photo looks down at the front of the dam where the penstocks emerge on their way to the powerhouse.

Why "Detroit?" you ask. The original settlers were mostly from Michigan, and they named their settlement after _that_ Detroit. Ironically, the original site is under the reservoir; the modern village was relocated out of the path of the lake.